Pretty much as long as you just ride and don't entertain yourself with non touring related activities , costs will reflect your usual daily living expenses.. eating out increases the costs significantly.. But, then stopping at sandwich shops, or grocery stores decreases those costs significantly.. As long as your camping isn't primitive , your nightly camping costs should be under 25 dollars tops, should you seek out state parks or city parks..
remember once being on tour, we ran into some bike tourer who was living on a shoe string but had traveled from New York to California.. His problem. He had to take the bus back to New York. He could not afford to feed himself, he was that broke.